为什么在洛谷平台上cin.getline()会读入一个\n到字符串里，本地就不会

不把len-1就会全WA

#include<iostream>
#include<cstdio> 
#include<cstring>
using namespace std;
int n;
char last;
char s[1000];
int calc(char* x,int len){
	int js=0;
    for(int i=0;i<len;i++)
		if(x[i]==' ')js++;
	return js;
}
int calc_1(char *x,int len){
	for(int i=0;i<len;i++)
		if(x[i]==' ')return i;
}
int calc_2(char *x,int len){
	for(int i=2;i<len;i++)
		if(x[i]==' ')return i;
}
int transform(char *x,int start,int end){
	int ans1=0;
	for(int i=start;i<=end;i++)
		ans1=ans1*10+x[i]-'0';
	return ans1;
}
int calc_len(int x){
	int ans=0;
	if(x==0)return 1;
	if(x<0){
		ans=1;
		x=-x;
	}
	while(x!=0){
		x=x/10;
		ans++;
	}
	return ans;
}
int main(){
	cin.getline(s,1000);
    int l=strlen(s);
    n=transform(s,0,l-2);
	for(int i=0;i<n;i++){
       cin.getline(s,1000);
		int len=strlen(s)-1;
		int judge=calc(s,len);
		if(judge==1){
			int pos=calc_1(s,len);
			int first=transform(s,0,pos-1);
			int second=transform(s,pos+1,len-1);
			int ans=0;
			if(last=='a'){
				ans=first+second;
				cout<<first<<"+"<<second<<"="<<ans<<endl;
			}
			if(last=='b'){
				ans=first-second;
				cout<<first<<"-"<<second<<"="<<ans<<endl;
			}
			if(last=='c'){
				ans=first*second;
				cout<<first<<"*"<<second<<"="<<ans<<endl;
			}
			cout<<len+1+calc_len(ans)<<endl;
		}
		if(judge==2){
			last=s[0];
			int pos=calc_2(s,len);
			int first=transform(s,2,pos-1);
			int second=transform(s,pos+1,len-1);
			int ans=0;
			if(s[0]=='a'){
				ans=first+second;
				cout<<first<<"+"<<second<<"="<<ans<<endl;
			}
			if(s[0]=='b'){
				ans=first-second;
				cout<<first<<"-"<<second<<"="<<ans<<endl;
			}
			if(s[0]=='c'){
				ans=first*second;
				cout<<first<<"*"<<second<<"="<<ans<<endl;
			}
			cout<<len-1+calc_len(ans)<<endl;
		}		
	}
	return 0;
}